Frequently Asked Questions on Scabies
What is scabies?
Scabies is an infestation of the skin by the human itch mite. A non-life threatening disease, symptoms of scabies include intense itching and a pimple-like rash. It is usually spread by direct, prolonged, skin-to-skin contact with a person. Sleeping with, or having sex with, any scabies-infested person presents a high risk for transmission. The longer a person has skin-to-skin exposure, the greater is the likelihood for transmission to occur. Although briefly shaking hands with a person who has non-crusted scabies could be considered as presenting a relatively low risk, holding the hand of a person with scabies for 5-10 minutes could be considered to present a relatively high risk of transmission. However, transmission can occur even after brief skin-to-skin contact, such as a handshake, with a person who has crusted scabies.
What is crusted (Norwegian) scabies?
Crusted scabies is a severe form of scabies – but, again, not life-threatening – that can occur in some people who are immunocompromised, elderly, disabled, or debilitated. Persons with crusted scabies have thick crusts of skin that contain large numbers of scabies mites and eggs. Patients with crusted scabies are very contagious to other people and can spread the infestation easily by both direct skin-to-skin contact and by contamination of items such as their clothing, bedding and furniture. Patients with crusted scabies may not show the usual signs and symptoms of scabies, such as the characteristic rash or itching. Persons with crusted scabies should receive quick and aggressive medical treatment for their infestation to prevent outbreaks of scabies.
How soon after infestation do symptoms of scabies begin?
If a person has never had scabies before, symptoms may take as long as 4-6 weeks to appear. It is important to remember that an infested person can spread scabies during this time, even if he/she does not have symptoms yet. In a person who has had scabies before, symptoms usually appear much sooner (1-4 days) after exposure.
How long can scabies mites live?
On a person, scabies mites can live for as long as 1-2 months. Off a person, scabies mites usually do not survive more than 48-72 hours. Scabies mites will die if exposed to a temperature of 50°C (122°F) for 10 minutes.
How is scabies infestation diagnosed?
Diagnosis of a scabies infestation usually is made based on the customary appearance and distribution of the rash and the presence of burrows (thin visible lines on the skin where the mite has dug). Whenever possible, the diagnosis of scabies should be confirmed by identifying the mite, mite eggs, or mite fecal matter.
What are the body parts most often affected by scabies?
The body parts that are most often affected by scabies are:
- The fingers and webbing between the fingers
- The skin folds around the wrists, elbows, and knees
- The armpits
- The area around the nipples (especially in women)
- The waist
- The penis and scrotum (in men)
- The lower buttocks and upper thighs
- The sides and bottoms of the feet
What is the treatment for scabies?
Treatment requires a doctor’s prescription, and typically involves the one-time application of a topical cream for 8-14 hours. When you start treatment, wash all the clothes you and others in your home wore in the last 4 to 5 days in hot water. Then dry them in a dryer on high heat. You should also wash any bedclothes (sheets and blankets) or towels that people in your home have touched. If your child is being treated, wash his or her stuffed animals, too. Dry cleaning will also get rid of the scabies mite. Any bedding, clothing, or towels that you cannot wash or dry clean should be placed in a sealed plastic bag for at least 3 days. Scabies mites usually die without contact with human skin after a few days. Alternative treatment options include an oral medication.
Anyone who is diagnosed with scabies, as well as his or her sexual partners and other contacts who have had prolonged skin-to-skin contact with the infested person, should be treated. Treatment is recommended for members of the same household as the person with scabies, particularly those persons who have had prolonged skin-to-skin contact with the infested person. All people should be treated at the same time to prevent re-infestation. Retreatment may be necessary if itching continues more than 2-4 weeks after treatment or if new burrows or rash continue to appear.
How soon after treatment will I feel better?
Most patients should feel better in 1-2 weeks. If itching continues more than 2-4 weeks after initial treatment or if new burrows or rash continue to appear, retreatment with scabicide may be necessary; seek the advice of a physician.
Can I get scabies from my pet?
No. Animals do not spread human scabies. Pets can become infested with a different kind of scabies mite that does not survive or reproduce on humans but causes “mange” in animals.
Can scabies be spread by swimming in a public pool?
Scabies is very unlikely to be spread by water in a swimming pool.
How can I remove scabies mites from my clothes, house, or carpet?
Scabies mites do not survive more than 2-3 days away from human skin. Items such as bedding, clothing, and towels used by a person with scabies can be decontaminated by machine washing in hot water and drying using the hot cycle or by dry cleaning. Items that cannot be washed or dry cleaned can be decontaminated by removing them from contact with people for at least 72 hours. Because persons with crusted scabies are considered very infectious, careful vacuuming of furniture and carpets in rooms used by these patients is recommended. Fumigation of living areas is unnecessary.
My spouse and I were diagnosed with scabies. After several treatments, he/she still has symptoms while I am cured. Why?
The rash and itching of scabies can persist for several weeks to a month after treatment, even if the treatment was successful and all the mites and eggs have been killed. Your health care provider may prescribe additional medication to relieve itching if it is severe. Symptoms that persist for longer than 2 weeks after treatment can be due to a number of reasons, including:
- Incorrect diagnosis of scabies. Many drug reactions can mimic the symptoms of scabies and cause a skin rash and itching; the diagnosis of scabies should be confirmed by a skin scraping that includes observing the mite, eggs, or mite feces (scybala) under a microscope. If you are sleeping in the same bed with your spouse and have not become re-infested, and you have not retreated yourself for at least 30 days, then it is unlikely that your spouse has scabies.
- Re-infestation with scabies from a family member or other infested person if all patients and their contacts are not treated at the same time; infested patients and their contacts must be treated at the same time to prevent re-infestation.
- Treatment failure caused by resistance to medication, by faulty application of topical scabicides, or by failure to do a second application when necessary; no new burrows should appear 24-48 hours after effective treatment.
- Treatment failure of crusted scabies because of poor penetration of scabicide into thick scaly skin containing large numbers of scabies mites; repeated treatment with a combination of both topical and oral medication may be necessary to treat crusted scabies successfully.
- Re-infestation from items such as clothing, bedding, or towels that were not appropriately washed or dry cleaned (this is mainly of concern for items used by persons with crusted scabies); potentially contaminated items should be machine washed in hot water and dried using the hot temperature cycle, dry cleaned, or removed from skin contact for at least 72 hours.
- An allergic skin rash (dermatitis); or
- Exposure to household mites that cause symptoms to persist because of cross-reactivity between mite antigens.
If itching continues more than 2-4 weeks or if new burrows or rash continue to appear, seek the advice of a physician; retreatment with the same or a different medication may be necessary.
If I come in contact with a person who has scabies, should I treat myself?
No. If a person thinks he or she might have scabies, he or she should contact a doctor. The doctor can examine the person, confirm the diagnosis of scabies, and prescribe an appropriate treatment. Products used to treat scabies in humans are available only with a doctor’s prescription.
If a co-worker is diagnosed with scabies, what precautions must be taken? Should the office be sprayed or fumigated?
Scabies usually is spread by prolonged skin-to-skin contact with a person who has scabies; persons who have had such contact should be evaluated by a physician and treated if necessary. Scabies mites do not survive more than 2-3 days away from human skin. Spraying or fumigating office or living areas is unnecessary.
When can I return to work if I am diagnosed with scabies?
In general, a person diagnosed with scabies could return to work 24 hours after being treated. In cases of crusted scabies or in outbreak situations, symptomatic healthcare workers that provide hands-on care to any patient must use disposable gloves for several days after treatment.
Can I get scabies from sharing an office chair or cubicle that is used by a person diagnosed with scabies?
Getting scabies from an office chair or cubicle that is used by a person with scabies is very unlikely.